Pg. 20-3 Step 4: Machine countersunk the designated holes in Center Section Assy. Dimpled the corresponding holes in the Center Section Aft Bulkhead. Step 7: Riveted the L&R Skin Attach Flanges to the Center Section Assy.
Pg. 20-4 Step 1: Attached the Center Section Aft Bulkhead and the L&R Aft Side Bulkheads to the Center Section Assy.
